" An interpretation which confines itself to the moral teachings of the gospel deprives Christianity of its historical and theological roots. Christianity without the Old Testament ceases to be Christianity and becomes quite a different religion, as the Fathers saw when they condemned the Gnostics, Marcion and the Manichees. The continuity of Christianity with the tradition of the Old Testament and the conception of the Church as the new Israel is a fundamental part of the Christian faith. "

― Christopher Henry Dawson , The Formation of Christendom